Lateralization of amygdala activation in fMRI may depend on phase-encoding polarity

  • Krystyna A. Mathiak
  • Mikhail Zvyagintsev
  • Hermann Ackermann
  • Klaus Mathiak
Short Communication

Abstract

Object

Susceptibility artifacts along the phase-encoding (PE) direction impact the activation pattern in the amygdala and may lead to systematic asymmetries. We implemented a triple-echo echo-planar imaging (EPI) sequence, acquiring opposite PE polarities along left–right PE direction in a single shot, to investigate its effects on amygdala lateralization.

Materials and Methods

Twelve subjects viewed emotional faces to evoke amygdala activation.

Results and Conclusion

A region of interest analysis revealed that the lateralization of amygdala responses depended on the PE polarity thus representing a pure method artifact. Alternating PE with multi-echo EPI reduced the artifact. Lateralized fMRI activation in areas with magnetic field inhomogeneities need to be interpreted with caution.

Keywords

Amygdala Lateralization Distortion correction Multi-echo fMRI 

Abbreviations

BOLD

Blood-oxygenation level dependent

EPI

Echo-planar imaging

FA

Flip angle

fMRI

Functional magnetic resonance imaging

FWE

Family-wise error

MDEFT

Modified driven equilibrium Fourier transform

MNI

Montreal Neurological Institute

PE

Phase-encoding

ROI

Region of interest

SPM

Statistical parametric mapping

TE

Echo time

TR

Repetition time

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Copyright information

© ESMRMB 2011

Authors and Affiliations

  • Krystyna A. Mathiak
    • 1
    • 2
    • 3
  • Mikhail Zvyagintsev
    • 4
    • 5
  • Hermann Ackermann
    • 2
  • Klaus Mathiak
    • 4
    • 5
    • 6
  1. 1.Department of Child and Adolescent Psychiatry, Psychosomatics and PsychotherapyRWTH Aachen UniversityAachenGermany
  2. 2.Center for Neurology, Hertie InstituteUniversity of TübingenTübingenGermany
  3. 3.Graduate School of Neural and Behavioural Sciences, International Max Planck Research SchoolUniversity of TübingenTübingenGermany
  4. 4.Department of Psychiatry, Psychotherapy and PsychosomaticsRWTH Aachen UniversityAachenGermany
  5. 5.JARA-Translational Brain ResearchJülichGermany
  6. 6.INM-1Forschungszentrum Jülich GmbHJülichGermany

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